1. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment SedFlume Findings and Initial 2D Sediment Model Results Conowingo Pond Conowingo Dam Susquehanna Flats S1

2. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment Topics: SedFlume Field Activities and Data Analysis Preliminary Sediment Transport Results with SedFlume Data S2

3. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment SedFlume Description Field – Portable Laboratory Flume Used to Evaluate Erosion Rate and Critical Shear of Cohesive Sediments S3

4. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S4 SedFlume Operations

5. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S5 Description of Sediment Coring Process

6. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S6 Sampling Locations in Conowingo Reservoir

7. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S7 SedFlume Analysis Core Lengths Varied From Approximately 6 – 12 inches The Entire Core was Analyzed Erosion Rate Coefficients and Exponents Evaluated by Layer Along with Critical Shear Stress for Erosion Core Bulk Density and Particle Size Distribution Evaluated

8. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S8 SedFlume Analysis Results

9. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S9 Example of SedFlume Results

10. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S10 Core Physical Properties Bulk Density Range – 1320 kg / m 3 to 1500 kg / m 3 Sediment Fractions Sand: 10% - 45% Silt: 50% - 82% Clay: 5% - 9%

11. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S11 SedFlume Data Assigned by Material Type in Model Model Domain Divided into Areas Based on Change in Properties Three Layers Assigned in Model Using Average SedFlume Data Average Sediment Size Fractions Assigned to Layers

12. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S12 Material Designation in AdH Model

13. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment 2D Model Development – 2008 Bathymetry S13

14. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S14 Preliminary Sediment Transport Simulation Evaluate the 2008 – 2011 Susquehanna River Flows Period of Record Includes the September 2001 Tropical Storm Lee Event Sediment Inflows Estimated From Previous HEC-6 Modeling

15. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S15 2008 – 2011 Susquehanna Flow Record

16. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S16 Sediment Rating Curve for 2008 – 2011 Simulation

17. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S17 Simulated Sediment Load in and out of Conowingo Reservoir: 2008 – 2011 Total In: 12 million tons Total Out: 16.6 million tons Net Scour: 4.6 million tons Assumptions: Top 1 ft layer critical Shear = 2 Pa Below 1 ft layer critical shear = 4 Pa

18. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S18 Computed Bed Shear Stress for 300,000 cfs

19. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S19 Computed Bed Shear Stress for 400,000 cfs

20. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S20 Computed Bed Shear Stress for 600,000 cfs

21. US Army Corps of Engineers Coastal and Hydraulics Laboratory Engineer Research and Development Center Lower Susquehanna River Watershed Assessment S21 Bed Change After the 2008 – 2011 Simulation